The present invention refers to an optical fiber connection device for being used with optical fibers embedded in composite structures. The invention further refers to a composite structure including the optical fiber connection device.
Within the field of structural health monitoring of composite structures, fiber optic-based sensors are increasingly advancing with regard to other conventional instruments, becoming the only solution for some applications. Within the family of fiber optic-based sensors, Bragg network-based sensors are highly used due to their great potential. This technology is particularly being developed for measuring and monitoring structural deformations in different types of structures, such as composites.
In aeronautical structures, traditional manufacturing processes for composites enable incorporating optical fibers within the material such that, after the polymerization of the composite, a unique material-sensor system is formed. This system constitutes a smart material with detecting capabilities potentially triggered by external excitations.
These smart materials are viable from a theoretical point of view, but are considerably difficult to implement on industrial level.
One of the main problems is on the intermediate face between the different materials, and in the particular case of composite structures with embedded fiber-optic sensors, the problem is in the transition between the composite structures and an external transmitting optical fiber, namely ingress-egress area.
Another problem comes on the area of the composite structure that contains the optical fiber since it presents different geometric and mechanical properties, introducing thereby a particularly delicate point in the composite structure.
Thus, integrating the optical fiber into composites structures by embedding them inside the lay-up is not only actually one of the most attractive solutions contributing to smart composite materials, but is the optimum approach able to ensure the maximum protection and integrity of the fibers inside the structural parts against the ambient.
Thus, the intended integration level is still a challenge since there are no industrial mature solutions today fulfilling with all main necessary requirements especially with reference to the ingress-egress of the optical fiber.
It would therefore be desirable to provide technical means that offer a solution for ingress-egress of the optical fiber in composite structures fulfilling with all the necessary requirements in the mentioned structures, while providing resistant and robust connection with the structure, together with all optical performance requirements such as minimum optical insertion losses.